Rotary casting



Jan. 8, 1929 R. B. DALE, ROTARY oAsTNG Filed Deo. 25. 1925 3 Sheets-Sheet 1 Inventor Jan. 8, 1929.

R. B. DALE ROTARY GSTING Filed Deo 25, 1925 5 Sheets-Sheet 2 Inventor? Attorney.

Patented Jan. 8V, 1929.

UNITED STATES tesam- PATENT OFFICE.

ROBERT BURDETTE DALE, OF JAMAIC,`NEW YORK, ASSIGNOR T0 WILLIAM W. WEITLING, F COLLEGE POINT, LONG ISLAND, NEW YORK.

ROTARY CASTING.

Application led December 23, 1925. Serial No. 77,188

This invent-ion relates to casting; is particularly useful in rotary casting; and is applicable, in connection with rotary or nonrotary moldsto thecasting of the ferrous metals, as iron and even steel.

The general advantages of the present invention may perhaps be most clearly indicated by a short discussion at this point of the importance of the invention in making ferrous castings in rotary'molds.

In t-he casting of ferrous metal articles such as iron or steel pipe, by the rotary or centrifugal method, there are two main object-s which must always be kept in mind,

where the mold is a permanent one in the sense that a considerable number of cast-ings are to be made without injuring the mold or its lining. Such a permanent mold must be used if the rotary method of manufacture is to be rapid and economical enough to warrant its installation. 'As far as I am aware, alll rotary casting methods heretofore proposed and now operating successfully or api parently capable of such operation, employ a permanent mold which is of metal.

v .Of the two main objects above referred to, which must always be kept in mind, one 1s .to insure that the ferrous casting 'shall not be chilled so that an annealing orother heat treating thereof is required after the castinga has been removed from the mold. The other main object to be kept in mind is to have j present as a feature of the process a method of or a means for exercisinga supervision and control over the -temperature 0f the mold` not only to provide a ferrous casting unchilled as above, but also to minimize abruptncss of mold temperature changes,.

particularly if the mold be a metal mold,

during the casting .operation and between successive casting operat-ions.

Such a method and means as that last described is disclosed in my copending application Serial N6. 749,476, filed November 12,

1924; where I propose the use of a metal structure including an inner mold proper or shaping member and an outer tubular member spaced from the mold proper to provide an annular chamber for contained mercury vapor. According to this arrangement, the pressure of the vapor jacket is raised and lowered at intervals during the casting operation and between-successive casting operations, thereby to raise and lower the temperations as` compared with steam. In said copending application, there is disclosed a plurality of rotary casting machines int/erconnected as to their annular chambers by way ofy a hermetically closed circulatory system for the mercury vapor to serve several or all the casting machines simul-` taneously but preferably differentially; s0

that one Aor more of such chambers may have the pressure of their vapor blankets increased wholly or partly as the result of decreasing the pressures of the vapor blankets of another or other machines. By such an arrangement fairly rapid production is possible from each of the machines; it'being clear that while one machine is receiving its charge of molten metal, another machine is spinning its previouslyreceived charge into shape and into set, another machine is spinning toA further set its casting, another machine is being stopped rotating preparatory to removing its casting, another machine has stopped rotating and is havin its casting removed, another machine is being inspected after the removal of its casting and being otherwise made ready for `spinning for receiving another charge, and so on, depending on the number of machines vin the set or battery of'each product-ion unit. According to said system, also, a mercury boiler or` boilers are incorporated .in the closed system, for replenishing the vapor supply should production be halted for an' unusually long time `forany reason; and the system also includes one or more condensers preferably forming parts of steam generators or other heat interchangers oreconomizers for excess t. u.s developed over a prolonged 'usefully/3'- abstracting the large number yof f cast-ing period during which castings are fmade at a fairly rapid rate. v

The-present invention aims to provide certain improvements in regard to a method and apparatus capable of being carried out by and embodied in a single casting machine such as that just described o1' an equivalent,

0r in a system such as that described or I an equivalent. These improvements have the particular object of making the process'w of said copending application a truly commercial one, and not only that but a highly leconomical and profitable one, because -of' greater ease of supervision and control ofthe `rate of congelation of a casting, and because offgreater speed in turning out each casting aswell as a given run of castings.

To these ends, the present invention aims to provide, among other things, first, a nieans'of and apparatus for spraying or ,chamber increases immensely the rate of cooling of thecasting, due to the heat ab'-,

sorbed by the liquid mercurywlien the saine is vaporized by contact with the walls of the chamber.

As the present invention is preferably carriedv out, the saine provides a method of and apparaus for (1) utilizing a predetermined vapor blanket `pressure to hold the mold temperature high enough, at or up to the introduction of a molten charge, to permit the molten metal to be held molten over a sufficient length of time to insure that the charge will properly distribute itself in the mold, however unevenly such charge be delivered to the mold; (2) thereafter utilizing another predetermined pressure to permit the casting to set at as rapid a'rate as possible aidyet .with that degree of slownessof's't'require'd toinsure that the third shrinkagel of the casting shall-ogcur before the precipitation of cementitefor otherwise to insure that the casting ,will so slowly'col downto a critical point that, how. ever rapidly thereafter the casting is cooled, the same will not after-removal from the mold be so much chilled as to require a subsequent annealing .or heat treating; (3) thereafter utilizing another predetermined pressure of the vapor and, in combination therewith, an injection of liquidmercury, to cool the castingbeyond said critical point at a very rapid'A rate, thereby very quickly. to impart to the 4casting such surface freeze or other rigidity that it may safely be removed from the mold; and (4) thereafter( utilizing another vpredetermined pressure of the vapor to raise the temperature ofthe mold to that high temperature referred 'to under (l), if another casting' is to be made during the run; while '(5) collecting and discharging practically as soon Vas collectedI frgm the annular chamber, all liquid mercury injected in excess of that evaporizedl according' to (3), and all liquid mercury condensed or 4otherwise accumulated in the chamber.

The invention will be more clearly understood from the following description, when taken in connection with the accompanying drawings, showing one possible apparatus adapted`to constitute a structural embodi- Fig. 1 show/5 a pipe casting machine in i side. elevation, certain of the hidden parts being shown in broken lines;

F ig. 2 1s an enlarged vertical axial section of the bell end of the mold;

Fig. 3 is a transverse section, taken` on the line 3 3 of Fig. 1; f

Fig. 4 is a vertical axial section of the opposite end of the mold, and v Fig. 5 is \an almost completely self-explanatory diagram relative to the casting of a cast iron pipe. i

The machine as shown in Fig. 1 includes a rotary struetureincluding an outer casing .5. This structure is journaled at opposite -ends in frames 6, and carries a center collar- \structure7 forming .part of the rotating drive. At 8 is indicated a core carrier, ro-

tary on a charge delivering spout 9 (so'that the. core carrier may rotate with the mold,

relative to tl'i'e spout); The spout is fed by hopper 10 on a pedestal 11 vertically pivoted on a wheel truck 12 ,so that during a casting operation, with the parts as shown, and assuming it is desired to cast a belled pipe', the core is` properly in the mold to make such bell therearou'nd, and. s o that, after a casting operation, the truck may bemoved on-its wheels suiiciently to tlie'left to permit the spout and core carrier to becleared from the mold, by swinging the pedestal on its pivot. Referring now, to Figs. f2, 3 and 4, it will.

be seen that said outer casing 5, carrying at opposite ends internal collar-structure 13 and 14, is neither the doublefwalled mold proper 15-15?t nor the outer tubular mem ber 16v surrounding the annular vapor chamber 17, 'but is a carrier for the parts last' of such collar-structures mentioned by way and also a housing mea-ns. for a mass of suitable heaty insulating material 18. p

In order hermetically to close the annular chamber 17 at the bell end of the machine,

lthe outer wall 15 of the mold proper is outwardly peripherally fianged as shown, and

welded to the tubular member 16 as indicated at 19 in Fig. 2; and, as shown in Fig. 4, the opposite endof the mold is closed by a circular plate 20 to which an inwardly bent peripheral portion of the wall 15 -of the mold proper is welded as indicated at 21.

The tubular member 16, which at the bell end of the machine is secured to collar-structure 13, is conically reduced beyond the other end of the mold proper and vthence extends to where it is secured to collar structure 14 at the oppositeiend ofthe machine. Beyond this point, an integral prolongation 16 of the tubular member rotates in a journal-box 22a formed in a frame 22.

As will be seen clearly from Figs. 2 and 4, the tubular member 16 is hollow from end 'to end, to form the annular chamber 17-as required and to permit mercury vapor to be admitted or to be drawn off, and to be changed in pressure and hence in temperature, by way of a single combined inlet and outlet at the free'end of the prolongation 16 of the tubular member 16, and by way of a suitable valve-served passage 23I formed in frame 22.

Beyond this passage 23, the frame 22 carries a journal-box 24- coaxial with the journal-box 22a, for receiving an end of a main feed tube 25 terminating at its op posite end in a conical manifold 26 serving a plurality of spiral spray tubes 27 for liquid mercury. Main tube 25, at its open end removed from said manifold, is in communication with a suitable valve-served passage 28 in frame 22.

Each of these spiral spray tubes is supported and rigidilied by beingA disposed, and secured if desired, against the advancing side (note the arrow of Fig. 3, indicating the direction of the rotation of the mold) of one of four spiral blades 29. These blades are suitably secured, as by welding, to the inner surface of tubular member 16, from well beyond the spacing collar 30 at the bell end of the machine as shown best in Fig. 2, to the outer or free end of the prolongation of 16 of the tubular member 16. Referring i-n this connection to Fig. 4, said blades of course are shaped in the vicinity ofl the conically reduced portion of the tubular member 16 and in the vicinity of the conical manifold 26 and the main tube 29a, to conform thereto, and are edge welded to the rounded surfaces thereof.

The mold proper 15--15a is of course centered in the tubular member 16 at the bell end of the machine by the means already described and including the welding 19 shown in Fig. 2. At the opposite end of the machine, the mold proper may be further secured and centered by incorporating such an arrangement as the collar-structure indicated at 31, which will be cut out at intervals allearound in order to permit passage of tlie blades and the spray tubes andv also to provide mercury vapor ports.

Said blades constitute in the machine illustrated, means for collecting and discharging liquid inercury in the annular chamber 17. Obviously, without such blades or some equivalent means, the faster the mold is rotated, the more securely will mercury in said chamber and particularly in the outlying portions thereof opposite the bell end of the mold, become trapped by centrifugal force, against removal by way of the bore lof prolongation 16 of the tubular structure 16; whereaswith such blades present, and arranged as shown, and the mold rotating as shown in Fig. 3, as soon as the mold is rotated at any speed bel-ow a permissible maximum, such liquid mercury will be collected, transported to and discharged from said bore. Hence, to remove liquid mercury, and to remove the same by discharging it into vapor passage 23thus to return the'liquid mercury preferably by way of a liquid trap, to the closed system for use therein as explained in the copending application aforesaid, it is only necessary to start rotating the mold at that speed whereat centrifugal force will not be so effective on the liquid as to interfere with the gravity action thereon This gravity action is that Vwhich causes the liquid actually to puddle, despite the rotation of't-he mold, in the bottom of annular chamber 17, there tov be picked up by the advancing side of a blade 29, and thereafter, consequently, to flow downwardly along said blade toward and through the bore in' prolongation 16 of tubular structure 16; as contrasted with the situation which would otherwise prevail when the mold would have to be stopped rotating and dismantled or up-ended in order to remove the liquid mercury.

From the explanations hereinabove, it will be seen that, during rotation of the mold, both gravity and centrifugal force alternately-act, in'an idea-l way,- to accomplish the desired result, which is to prevent clearing. and to clear, the annular chamber 17 of liquid mercury, atcertain appropriate intervals in the cycle of the making of a single casting or a run of castings. Thus, whenever the mold-temperature is to be affected by the removal of liquid mercury, whether the latter be that injected as such orlliquid previously condensed from mercuryl vapor, themold isfalways rotating, and what gram, the showing assumes the making of cast 1ron pipe; and that, 1n sald diagram, no

.attempt has been made to include or otherwise indicate time intervals or relations by lengths of various portions of the curves or by relations between such curves or their port-ions. In this diagram, the legend L.

M.-Egress speed, the L. M. standing for clusions of the operations described are, in-

dividually, particularly susceptible of variation under different conditions. including a run of castings, the two main curves will repeat on themselves, as by ima inin@r the oint C each time the pointg D P a 'IC is reached, to become projected to 'the lo- 'cation of the point C. Itbein inallv noted that the legend Critical point refers to the critical point hereinabove mentioned, it is believed -that further explanation of the diagram is unnecessary. s

Obviously, the present invention is 'not to be limited to the castinggof ferrous metals, or indeed the casting of any metals; or to casting in centrifugal or rotary molds. Nor

is the invention tobe limited to a utilization necessarily involving a permanent mold which ishof met-al, or even a permanent mold of any kind. Further, the invention is not to be limited to the casting of elongate articles of circular cross section such as pipe,

or even disk-like articles such as car wheels. Again, the invention is not necessarily to be limited to mercuryvapor and liquid mercury if another vapor and another liquid, whether or not such vapor be merely said liquid. in another form, be` found susceptible of employment according to the broad principles of the invention. In other words it i and described herein bein invention as now is emphasized, again, that the pending claims are' to be looked -to solely, for the definition of the real fundamentals of the present invention;v all other things shown merely illustrative of a preferred mode o carrying out the l understood.

1. In the art of rotary casting, the method of affecting the rate at which the mold and mold-coadjuvant parts of a casting machine.

absorb heat from a material being cast in the mold, which involves bringing `a metallic liquid having a va orization temperature considerably lower t an zinc, into contact with one of such heat-absorptive parts.

2. In the art of rotary casting, the-method o f affecting the rate at which the mold and mold-coadjuv'ant parts of a casting machine In a cycle absorb heat from a material being cast in the mold, which involves directing a liquid -metal into heat-absorptive relation to the y'the mold, which involves spraying a liquid against one of such heat-absorptive parts, and utilizing-centrifugal force to distribute the sprayed liquid.

5. In the art of rotary casting, the method of ali'ecting the rateat which the mold absorbs heat from a material being cast V therein, which involves bringing a non-oleaginous liquid into heat-exchanging relation with thejmold, said liquid being vaporizable at a higher temperature than water but at a lower vtemperature than zinc.

6. In the art of rotary casting, the method of affecting the rate at which the mold ab- Y sorbs heat `from a material being cast there- 1n, whlch involves brlngmg a non-a ueous and non-oleaglnous liquld and a liqui free ot' considerable uantities of lead, yzinc or tin,

into heat-intero anging relation with the mold.

7. In the art of rotary casting, the method of ai'ecting the rate at which the mold and mold-coadjuvant parts of a casting machine absorb heat from a material being cast in the mold, which involves spraying a liquid into heat-exchanging relation to one of such heat absorptive parts in a plurality of jets, in non-straight-lme relation.

8. In the art of rotary casting, the method of aecting the-rate at which the mold and mold-coadjuvantparts of a casting machine absorb heat from a material being cast in ,the mold, which involves spraying a liquid into heat-exchanging relation to. one of such heat-absorptive parts in a plurality of jets circumferentially spaced.

9. In the art of rotary casting, the method of affecting the rate at which the mold and mold-coadjuvant parts of a casting machine absorb heat from a material being cast in the mold, which involves spraying a liquid into heat-exchanging relation to one of such heatabsorptive parts in a plurality of jets arranged in a plurality of substantially parallel lines. v i

10. In the art of rotary casting, the method of affecting the rate at which the mold and mold-coadjuvant parts of a castmesses nately predeterminedly bringing into heat-- exchanging relation with the mold, a vapor under a given pressure, a liquid, and a va or under a different pressure from that rst mentioned.

13. In the art of rotary casting, the method of affecting the rate at which the mold absorbs heat, which involves alternate ly predeterminedly bringing into heat-exchanging relation With the vmold a liquid, and a vapor under a predetermined pressure.

14. In the art of rotary casting, the

method of affecting the rate at which thel mold absorbs heat, which involves maintaining a vapor in heat-exchanging relation with the mold, at intervals bringing a liquid into heat-exchanging coaction with said vapor relative to the mold, and at intervals removing a part of said liquid from such coaction.

15. In the art of rotary casting, the method of using a liquid, and a vapor in confinement, for coacting to aiect the rate of heat-absorption of the mold, which involves employing centrifugal force to distribute said liquid relative to the vapor.

16. In the art of rotary casting, the .method of using a liquid, and a vapor in confinement, for coacting to aiect rthe rate of heat-absorption of the mold, which involves employing centrifugal. force to distribute said liquid relative to the vapor and gravity to collect said liquid for discharge from said confinement.

17.'In the art of rotary casting, the method of using a liquid, and a vapor in confinement, for lcoacting to affect the rate of heat-absorption of the mold, which involves employing mold-rotation to discharge said liquid from such confinement.

18. In the art of rotary casting, the method of using a liquid, and a vapor in confinement, for coacting to aii'ect the rate of heat-absorptionof the mold, which involves employing mold-rotation to segregate said liquid from the vapor, While conning the liquid and the vapor in predetermined adjacency to the mold, and also positivelyto discharge the liquid from said confinement.

19. In the art of rotary casting, the method of using a medium in vapor form to affect the rate of heat-absorption of the mold, such liquid becoming liquid at a certain temperature;.which involves confining such vapor in predetermined adjacency to the mold and utilizing mold-rotation to remove from said adjacency apart of the medium becoming liquid While in such ad'acency.

20. In rotary casting, the met od of affecting the rate of congelation of a casting, which involves subjecting such casting to heat-exchanging relation With mercury vapor, and simultaneously to'similar relation with a liquid.

21. In rotary casting, the method of affecting the rate of congelation of a casting, which involves subjecting such casting to heat-exchanging relation with a vapor, and simultaneously -to similar relation With liquid mercury. l

22. In rotary casting, the method of affecting the rate of congelation of a casting, Which involves subjecting such casting to heat-exchanging relation With mercury vapor, and simultaneously to similar relation with liquid mercury additional to any liquid mercury then in such relation as the result of condensation from mercury vapor previously in suchA relation.

23. In rotary casting, the method of affecting the rate of congelation of a casting, which involves subjecting such casting to heat-exchanging relation with mercury vapor, and simultaneously to similar relation with liquid mercury, and then to similar relation with such vapor and a less amount of such liquid.

24. In the art of rotary casting, the method of affecting the rate at which the mold absorbs heat from a material being cast therein, which involves providing a jacketed mold, and spraying a liquid into the jacket during setting in the mold of the material being cast.

25. In the art of casting, the method of afecting the rate at which the mold absorbs heat from a material being 'cast therein, which involves providing a jacketed mold, and spraying a liquid into the acket during setting in the mold of the material being cast.

26. In the art of casting, the method of affecting the rate at which the mold absorbs heat from a material being cast therein, which involves bringing a non-aqueous and non-oleaginous liquid and a liquid free of considerable quantities of lead, zinc or tin,

linto heat-interchanging relation with the mold.

27. In the art of casting, the method of affecting the rate at which the mold and." mold-coadjuvant parts of a casting machine absorb heat from a material being cast in the mold., which Iinvolves spraying a liquid aecting the rate at which the mold absorbs v heat, which involves alternately predeterminedly bringing into heat-exchanging relation with the mold a liquid, and a vapor.

29. In the art of casting, the method of ali'ecting the rate at which the mold absorbs heat, which involves alternately predeterminedly bringing into heatexchanging relation with the mold, afvapor under a given pressure, a liquid, and a vapor under a dif-- ferent pressure 'from that first mentioned.

30. In the artof casting, the method of affecting the rate at which the mold absorbs heat, which involves alternately predeterminedly bringing into heat-exchanging relation with the molda liquid, and a Vapor under a predetermined pressure.

311 In the art of casting, the method of affecting -the rate at which the mold absorbs heat, which involves maintaining a vapor in heat-exchanging relation with the mold, at4

intervals, bringing a v liquid into 'heat-exchanging coaction with said vapor relative to the mold, and at intervals removing a part of said liquid from such coaction.

32. In casting, the method of affecting the rate of congelation of a casting, which involves subjecting such casting to heat-exchanging relation with mercury vapor, and simultaneously to similar relation with a liquid.

33. In casting, the method of affecting the vrate of congelation ofa casting, which involves subjecting such casting to heat-exchanging relation with a vapor, and simultaneously to similar relation with liquid mercury.

34. In casting, the method of aecting the rate of congelation of a casting, which involves subjecting such casting to heat-exchanging relation with mercury vapor, and simultaneously to similar relation with liquid mercury additional to any liquid mercury then in such relation as the result of condensation from mercury vapor previously in such relation.

35. In casting, the method of ali'ecting the rate of congelation of a casting, which involves subjecting such casting to l1eatex changing relation with mercury vapor, and simultaneously to similar relation with liquid mercury, and then to similar relation .with such vapor and a less amount of such liquid.

casting in the mold, a liquid, and a vapor.

37. A method according to claim 36, charwherein said vapor is mercury vapor.

under another pressure.

38.` A method accordingvto claim 36, characterized by causing the vapor and the liquid A to coact heat-exchangingly, and removing some or alll of said liquid from such coaction, said vapoibeing the vapor of a liquid existent as a vapor at a high temperature and low pressure as compared with steam.

39. A method according to claim 36, wherein the'liquid and the vapor are used in coninement, for coacting to affect the rate of-heat absorption of the mold, and there'- With the rate of congelation of a casting in the mold.

40. A method according to claim 36, wherein'centrifugal force is employed to distribute said liquid relative to the vapor and gravity to collect said liquid for discharge from said confinement.

41. A method according to claim 36, characterized by employing mold-rotation to segregate said liquid from the vapor and to positively discharge the liquid from such relation.l

42. A method according to claim 36,

44. A method according to claim 36,

45. A. method according to claim 36, wherein Said liquid is liquid mercury and said vapor is mercury vapor, and wherein said liquidmercury is deliberately added as anaddition to liquid mercury then present as the-result of condensation.

46. A rotary metal casting apparatus having a rotary mold and a vapor chamber as- Sociated therewith in heat exchanging relation thereto in combination with meansv for at will admitting vapor to said chamber, and means for spraying liquid into said chamber.

47. A rotary casting apparatus according to claim 46, includilg means for moving any such liquid in the chamber axially of the mold.l

48. A rotary casting apparatus according to claim 46, including a spiral blade arranged in said chamber and adapted -to move said liquid axially toward anoutlet `lof said lchamber on rotation of the mold below a tary mold absorbs heat from a chargeof ferrous molten metal supplied thereto from a casting therein, which involves introducing said chargeinto the mold after the mold has been suitably heated up to a temperature sulicient to insure that said charge ollow' ing said introduction will distribute itself properly in the mold due to centrifugal force to form the desired casting, then holding in a' chamber close to the mold a Vapor at a temperature and pressure suiicient to permit the casting to set with that degree of slowness down to 'a critical temperature point required to insure' that the casting after being thus cooled down to sai'dpoint may 'thereafter be cooled at a faster rate than before yet without the creation finally of a chilled casting, and then injecting liquid into said chamber at a temperature to be vaporized by the mold temperature and thereby Ito utilize the latent heat of vaporization principle .to abstract heat units quickly from the mold and hence from the casting in the latter, thereby in turn,for speed production purposes,'to hasten the reaching by the casting` ofa sulicient rigidity to permit safe extraction ofthe casting Jfrom the mold.

Signed at New York in the county of New York and State of New York` this 19th day 25 of December', A. D. 1925.

R'BURDETTE DALE. 

